In a random sample of 20 NBA basketball games the mean number of points scored by the home team was 100.4 with a standard deviation of 4.86.
Create and interpret a 95% confidence interval for the true mean number of points scored by an NBA basketball team at home.
You and your friend were watching a LA Lakers game where they were not playing at home. They only scored 98 points. Your friend says, "Wow, I bet if they were playing at home they would have scored a lot more points." Do you agree or disagree with your friend? Support your detailed answer.

Respuesta :

Answer:

The  95% confidence interval is  [tex]98.27 < \mu < 102.53[/tex]

This interval means that there 95% confidence that the true mean is within this interval  

Yes i would agree with my friend because the lower and the upper limit 95% confidence interval for mean points scored at home is greater than 98 points

Step-by-step explanation:

From the question we are told that

   The  sample size is  n =  20

   The  sample mean is  [tex]\mu = 100.4[/tex]

     The standard deviation is  [tex]\sigma = 4.86[/tex]

 

Given that the confidence level is  95% then the level of significance is mathematically evaluated as

                [tex]\alpha = 100 - 95[/tex]

               [tex]\alpha = 5\%[/tex]

                [tex]\alpha = 0.05[/tex]

Next we obtain the critical value of [tex]\frac{ \alpha }{2}[/tex] from the normal distribution table, the value is  

           [tex]Z_{\frac{ \alpha }{2} } = 1.96[/tex]

Generally the margin of error is mathematically represented as

           [tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma}{ \sqrt{n} }[/tex]

substituting values

            [tex]E = 1.96 * \frac{ 4.86 }{ \sqrt{20 } }[/tex]

           [tex]E = 2.13[/tex]

The  95% confidence interval is  mathematically represented as

          [tex]\= x - E < \mu < \= x + E[/tex]

substituting values

         [tex]100.4 - 2.13 < \mu < 100.4 + 2.13[/tex]

          [tex]98.27 < \mu < 102.53[/tex]